Condensation and turbulence modeling of crisscross mesh for fog harvesting toward sustainable water production

Water vapor condenses into liquid when the air temperature drops to the dew point, causing the molecules to slow down and form droplets. This process depends on the humidity and temperature of the surrounding air, as cooler air can hold less moisture, allowing water to accumulate on cold surfaces. Behind the fog harvesting system, the physics of condensation process works meshes are designed from special materials to capture fog. However, the behavior of droplets on these nets/meshes under airflow is not fully explored, making it challenging to predict droplet movement, merging, and drainage. Therefore, this study investigates how droplets on crisscross mesh surfaces interact with each other in foggy airflow at different temperatures. The performance of fog harvesting systems is influenced by mesh material, geometry, fog density, and wind speed. The computational model uses single phase transport equations coupled with the (Formula presented) SST (a blend of (Formula presented) and (Formula presented) models) RANS turbulence model. The blending function F1 is used as a switch between (Formula presented) and (Formula presented) models. The steady turbulent multiphase flow of air and vapor is computed to improve the efficiency and performance of the fog collector mesh. Artificial compression is introduced in the model to analyze the behavior of fog harvesting on mesh surface. The physics behind the condensation and its role on fog harvesting is presented in detail. The proposed model consist of nonlinear equations are solved via Finite Volume Method (FVM) in OpenFOAM. These findings provide practical guidance for designing effective fog harvesting systems. The results obtained can lead to more efficient and sustainable fog water collectors.